1. Field of the Invention
The invention relates generally to chemical process optimization. More particularly, the invention relates to chemical process optimization while considering chemical process plant safety.
2. Description of the Related Art
Many industrial chemicals are produced in generally large volumes (i.e., thousands of tons per year) while using chemical process plants. Chemical process plants may be used for producing organic chemicals (i.e., including petrochemicals), as well as inorganic chemicals. Chemical process plants may in general be used for producing chemicals within either a batch processing mode (i.e., a batch processing using a batch chemical process reactor) or alternatively a continuous processing mode (i.e., a continuous processing using a continuous chemical process reactor).
When producing chemicals in general, and when producing organic chemicals more particularly, it is common in the chemical processing art to react a chemical reactant material under elevated conditions of temperature and pressure to facilitate an efficient chemical reaction of the chemical reactant material to a desirable chemical product material. In many chemical reactions, at least one of a chemical reactant material and a resulting chemical product material may be chemically unstable (i.e., readily prone to a chemical reaction). The presence of at least one of a chemically unstable chemical reactant material and a chemically unstable chemical product material within a chemical reactor may lead to safety considerations within a chemical process plant within which the chemical reactant material is reacted to produce the chemical product material. As a non-limiting example, olefin oxidation reactions (i.e., olefin epoxidation reactions), such as a reaction of ethylene and oxygen to produce ethylene oxide, are particularly susceptible to flammability due to the presence of an oxidation prone organic chemical reactant material (i.e., an olefin) in the presence of an oxidant (i.e., oxygen).
As background, various aspects of ethylene oxide production incident to reaction of ethylene and oxygen at elevated temperature and elevated pressure within a chemical process plant are known in the chemical process art.
For example, Evans et al., in U.S. Pat. No. 6,372,925, World Pub. No. WO/2004/092148 and U.S. Pub. No. 2004/0236124, teaches a chemical process for production of ethylene oxide by reaction of ethylene and oxygen, while considering an aging effect of a selective silver catalyst that is used within the chemical process. Due to consideration of the aging effect of the selective silver catalyst, the chemical process provides for using different reaction temperatures and different ethylene oxide chemical reactant concentrations before and after aging of the selective silver catalyst that is used within the chemical process.
In addition, Gary et al., in U.S. Pat. No. 7,153,985, teaches a chemical process for producing ethylene oxide by reaction of ethylene and oxygen, while avoiding a post-ignition condition within a chemical process plant within which is undertaken the chemical process. The post-ignition condition within the chemical process plant is avoided in-part by monitoring a concentration of hydrocarbons having at least four carbon atoms within the chemical process plant as an indication of susceptibility of the chemical process plant to the post-ignition condition.
Chemical process plant safety is likely to continue to be of considerable importance within the context of implementation of new and existing chemical processes within chemical process plants. To that end, desirable are general methods that may be used to assure chemical process plant safety when implementing new or existing chemical processes within the chemical process plants.